they gave me a form to send it to her. Shall I also write her a letter or no? I think the form should be enough to be firm.

My question is am I supposed to send her a Court application or Court forms just to show her that if she does not reply, I am determined to sue her. ?? Help! I live in Chicago
Although it would be satisfying to bully her it could back fire on you. On the top of your letter write:

Demand Letter

I, under your name, are requesting the return of $amount of money or a complete accounting with receipts & pictures of all or any costs use from my deposit to repair the unit located at put address with apt #. This information is to be delivered 7 business days from today no later than 5:00 p.m. of on put day. If I do hear from you by this time I will believe that you do not wish to comply and I will seek out legal recourse's.

Respectfully,

your name

you can also list your phone number, but it is always best to have hard copy information.
I am a landlord.

Most states require a deposit to be returned within a certain amount of days. Even if you don't demand it, if the landlord doesn't either give you your entire deposit back, or partial or zero deposit along with a "final accounting" form, you may legally be entitled to receive back your entire deposit plus extra.

How long has it been since you moved out? If over 30 days, you are probably entitled to a final accounting explanation. If it's not in writing, it doesnt' count.

Did you owe late fees or back rent? Deposits in most states may be kept for the purposes of paying late rent. Again, she would need to supply you with a final accounting form or letter explaining what part of your deposit, or all of it, was applied to past-due rent.

Was there damage to the property? Obviously if there was, the purpose of a deposit is to cover its repairs. Still, she will need to account for what was spent in writing.

Hope this helps. Also, avoid acting out or retaliating. If this goes to court, you will just look immature. Do the right thing and send a demand letter (see a previous post about this). If you scare her or retaliate, she may counter-sue you if you go to court.
Court forms are just paper if you did not file them and they are not stamped by the courts.

You sound more like you want to give her a good laugh.

Write her a letter asking for an explanation on why your deposit was not returned. It is not a given that you will receive it. To receive it you need to have the place spotless and not owe her money for anything.
Just send her the form along with a return address. She either has to return the deposit or give you in writing why she won't. I hope you took pictures and did a walk through with her. Send the letter certified, signed receipt requested.
put a white sheet over your head and jump out and scare him in the middle of the night or you could send her a copy of the form too as she know's whats going on. you might not be the most favourable tenant in the world though if you go down the that road.
Small Claims Court .. you can do it all on-line ..

whoops, just spotted you are not in UK (odd, I'm sure this is the UK forum …)

Anyway, link below may help others so I'm leaving it in …
Make a copy of the form. Send the form certified and make her sign for it. Then go back to the tenants organization and ask them the next step.